No contribution of GSTM1 and GSTT1 null genotypes to the risk of neutropenia due to benzene exposure in Southeastern Brazil

Exposure to benzene has been associated with haematological diseases such as neutropenia (NEB) and acute myeloid leukaemia (AML). We tested whether the null genotypes of the GSTM1 and GSTT1 genes, involved in benzene inactivation, altered the risk for NEB in southeastern Brazil. Genomic DNA from 55 NEB patients and 330 controls was analysed by multiplex-polymerase chain reaction. The frequency of the GSTM1, GSTT1 and combined null genotypes was similar in patients and controls (GSTM1, 27.3% vs. 38.8%, p = 0.16; GSTT1, 25.5% vs. 19.7%, p = 0.24; GSTM1/GSTT1, 12.7% vs. 6.7%, p = 0.26; respectively). The distribution of genotype classes in NEB patients was similar to normal controls, suggesting that GSTM1 and GSTT1 null genotypes make no specific contribution to the risk of NEB. As the GSTM1 and GSTT1 null genotypes were previously associated with increased risk for AML in Brazil and elsewhere, we hypothesise that different thresholds of chemical exposure relative to distinct GSTM1 and GSTT1 genotypes may determine whether AML or NEB manifests in benzene exposed individuals from southeastern Brazil. Although indicative, our results still require support by prospective and large scale epidemiological studies, with rigorous assessment of daily chemical exposures and control of the possible contribution of other polymorphic genes involved in benzene metabolism

Reticulocyte parameters and hemoglobin F production in sickle cell disease patients undergoing hydroxyurea therapy

Hemoglobin F (HbF) is an effective inhibitor of HbS polymerization. Hydroxyurea (HU) is used to increase HbF synthesis and improve the clinical course of sickle cell disease (SCD) patients. We studied a series of laboratory parameters concerning HbF production and reticulocyte response, and compared data between two groups: 1) 13 SCD patients treated with HU, and 2) 33 untreated SCD patients. Higher values of Hb concentration, mean cell volume (MCV), mean cell hemoglobin (MCH), mean reticulocyte volume (MRV), HbF concentration, percentage of F-cells, and amount of HbF/ F-cells were observed in the treated group of patients. There was no correlation between Hb and HbF elevations. The reticulocyte count, immature reticulocyte count, mean fluorescence index (MFI), and neutrophil count were significantly lower in treated patients. Taken together, these findings suggest that a decreased hemolytic process occurred in patients undergoing HU treatment. There was a significant correlation between MCV and a HbF, between MRV and HbF, and between MRV and F-cell in patients taking HU. These data indicate that macroreticulocytes correspond to F-reticulocytes, and that an increase in MRV in SCD patients using HU may be an indirect signal of F-cell production. The concentration of HbF/F-cells was higher in patients treated with HU, but this increase apparently was independent of F-cell production. Reticulocyte (RTC) parameters, as assessed by hematological analyzers, may be useful for following erythropoietic changes in patients receiving HILI, and can indirectly indicate HbF and F-cell production induced by HU therapy. J. Clin. Lab. Anal. 17:66-72, 2003. (C) 2003 Wiley-Liss, Inc.172667

Camptothecins Compared with Etoposide in Combination with Platinum Analog in Extensive Stage Small Cell Lung Cancer Systematic Review with Meta-Analysis

Introduction: Superiority of camptothecin regimens over etoposide-both combined with platinum analogs-in extensive disease small cell lung cancer has been a matter of debate with contradictory findings in randomized trials. A systematic review was sought to elucidate this issue. Methods: Randomized controlled trials comparing first-line camptothecin-platinum doublets versus etoposide-platinum doublets in patients with extensive disease small cell lung cancer were searched in MEDLINE, EMBASE, LILACS, and CENTRAL databases, European Society of Medical Oncology, American Society of Clinical Oncology, and International Association for the Study of Lung Cancer meeting sites. Meta-analyses were performed using fixed-effects model. Subgroup analyses were undertaken comparing each type of camptothecin to etoposide-based regimens. The outcomes of interest were overall survival (OS), progression-free survival (PFS), response rate (RR), and toxicities. Results: Eight studies (3086 patients) were included. The meta-analysis of topotecan regimens (TP) was not reliable due to impending heterogeneity. Meta-analysis of trials testing irinotecan combinations (IP) versus etoposide regimens (EP; 1561 patients) stated an OS improvement in favor of IP arm, though with considerable heterogeneity, whose origin seemed to be a Japanese trial. In the analyses without that study (1407 patients left), IP brought a significant improvement in OS (hazard ratio = 0.87; 95% confidence interval 0.78-0.97; p = 0.02; I(2) = 0). IP also increased PFS (hazard ratio = 0.83; 95% confidence interval 0.73-0.95; p = 0.006; I(2) = 0%). There was no impact in RR (absolute RR 56% with IP; 53% with EP; p = 0.17). IP caused more diarrhea (p < 0.0001) but less hematological toxicities (p < 0.001) than EP. Conclusions: The present meta-analysis demonstrates statistically significant OS and PFS benefits of IP over EP regimens in western and eastern patients. Specific characteristics of safety profile should be taken into account when administrating IP chemotherapy.5121986199

Polymorphism of cytochrome P450 A2 (CYP1A2) in pure and mixed breed dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)342184186Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Low incidence of human herpesvirus 8 in bone marrow samples from Brazilian patients with multiple myeloma

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CYP1A1, GSTM1 and GSTT1 polymorphisms, tobacco and alcohol status and risk of head and neck squamous cell carcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We examined the influence of the CYP1A1 A4889G and T6235C, GSTM1 and GSTT1 polymorphisms, involved in carcinogen metabolism, on the head and neck (HN) squamous cell carcinoma (SCC) risk. DNA from 142 HNSCC patients and 142 controls was analysed by polymerase chain reaction (PCR)-restriction fragment length polymorphism or multiplex-PCR for the polymorphisms analyses. Excesses of the CYP1A1 4889AG+GG and 4889AG+GG plus GSTT1 null genotype were seen in patients with heavy tobacco habit compared with controls (41.9% versus 26.8%, P=0.03; 26.2% versus 10.3%, P=0.04, respectively). Carriers of the referred genotypes and heavy tobacco consumption were under a 2.0-fold and 2.8-fold increased risks for HNSCC than others, respectively. The CYP1A1 6235TC+CC plus GSTM1 and GSTT1 null genotypes were more common in pharyngeal SCC patients than in controls (5.3% versus 0.7%, P=0.04). Carriers of the combined genotype had 16.0-fold increased risk for the disease than others. The frequency of one null genotype of the GSTM1 or GSTT1 gene was higher in patients with pharyngeal SCC and heavy smoking status than in controls (76.3% versus 57.7%, P=0.04). Carriers of the referred genotype and heavy tobacco status had a 2.4-fold increased risk for pharyngeal SCC than others. In contrast, the CYP1A1 6235TC+CC genotype was more common in controls than in laryngeal SCC patients (35.9% versus 21.6%, P=0.01). Carriers of the genotype had a 0.2-fold decreased risk for the disease than others. Our data present preliminary evidence that inherited combined CYP1A1 A4889G and T6235C abnormalities and GSTM1 and GSTT1 pathways are important determinants of HNSCC, particularly pharyngeal SCC in heavy smoking individuals from southeastern Brazil.32612091215Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Financiadora de Estudos e Projetos do Ministerio da Ciencia e Tecnologia do Brasil (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Phenotypic quantitative features of patients with acute myeloid leukemia

The recent WHO classification for acute myeloid leukemias (AML) separates entities by recurrent cytogenetic abnormalities and immunophenotypic features presenting prognostic impact. We have examined the expression of several lineage and maturation linked antigens used in routine immunophenotyping of patients with de novo AML, using a 3-color two-step panel. Cases were diagnosed by peripheral blood counts, bone marrow cytology, cytochemistry, cytogenetics and immunophenotyping (CD2, CD3, CD7, CD19, CD13, CD33, myeloperoxydase-MPO, CD14, CD15, HLA-DR, CD34, CD56 and CD45). Antigen expression was measured by mean fluorescence intensity (MFI) by flow cytometry (Paint-a-gate software). Thirty five patients were analyzed. Median age: 51 years (15-79). Predominant FAB types were M2 and M4. In 6 cases more than one phenotypically distinct blast subpopulation could be detected. Although our set was small, we tried to analyze the impact of MFI of the examined antigens on the overall survival of the patients. In Cox univariate analysis, age, peripheral leukocytes (W BC) at diagnosis, MFI of CD45, and MPO were significant for worse a survival. In the multivariate analysis only MFI of CD45 and WBC remained in the model (p=0.018 and p=0.014 respectively). After bootstrap resampling, MFI of CD45 entered the model in 69%, WBC in 60%, age in 42% and MFI of MPO in 35% of the sets. Analysis of antigen expression by MFI permitted to detect cases presenting phenotypically distinct blast subpopulations. This may represent a pitfall in studies of minimal residual disease by flow cytometry, as chemotherapy may select one of these subsets.53215516